Thickening Agents
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
Xanthan gum is a natural-derived, high molecular weight polysaccharide used to thicken and stabilize suspensions, emulsions and foams against separation. The high viscosity associated with xanthan gum solutions at low shear rates enables products to keep particles suspended or prevent oil droplets from coalescing. As the gum exhibits pseudoplastic rheology, the viscosity drops when shear is applied, therefore the end product can be easily scooped, poured or squeezed from its container. Once the force is removed, the solution regains its initial viscosity almost immediately, thereby stabilizing the formulation. Xanthan gum is soluble in hot or cold water; stable over a wide range of pH and temperatures; resistant to enzymatic degradation; and has excellent compatibility in the presence of anionic, amphoteric, nonionic surfactants and high concentrations of salt. Applications include body wash, shampoo, shower gel, hair gels, lotions, creams and conditioners.
Polysaccharide-Based Polymers in Cosmetics
E. Desmond Goddard, James V. Gruber in Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
Another rheologically interesting feature of kappa-carrageenan is the unique and synergistic viscosifying effect seen in blends with either a galactomannan (e.g., konjac mannan) or a glucomannan (e.g., locust bean gum) (Fig. 12) (The structure of the gluco- and galactomannans will be discussed in more detail later in this chapter.) Details of the interaction are still being debated. The synergy manifests itself in higher solution viscosities and elastic modulii as shown in Figure 13 for blends of к-carrageenan and galactomannan. The prevailing concept is that gluco- and galactomannans bind to the kappa-carrageenan double helix, interrupting the salt-induced large-scale aggregations of the double helices, increasing the number and strength of the junction zones, and causing stronger gels. Regardless of the mechanism, formulators find that adding one of the abovementioned gluco- or galactomannans to a solution containing kappa-carrageenan further increases its viscosity. Mixing of the two synergistic polysaccharides and the salts of the formulation, however, must be carefully controlled to achieve maximum performance. Xanthan. Xanthan gum is an anionic polysaccharide made commercially by bacterial fermentation. It occurs as an exocellular coating on the bacterial cell walls and is isolated after the fermentation process by precipitation from the broth Structur-
Grains
Christopher Cumo in Ancestral Diets and Nutrition, 2020
Manufacturers leverage fear—a primal emotion that tends to overwhelm the capacity for deliberation—by offering gluten-free products whose ingredients include “tapioca, corn, rice flour, potato starch, and xanthan gum.”62Chapter 13 defines tapioca as cassava starch, which lacks micronutrients.63 Later sections discuss corn and rice’s health effects in prehistory and history. Chapter 13 amasses evidence that the potato (Solanum tuberosum) is the world’s most nourishing food. Like tapioca, however, potato starch is just carbohydrates without additional nutrients.64 Fermented from sucrose, mentioned earlier and discussed in Chapters 2 and 11, xanthan gum lacks nutrients and may impair breathing and digestion.65
Self-double-emulsifying drug delivery system incorporated in natural hydrogels: a new way for topical application of vitamin C
Published in Journal of Microencapsulation, 2018
Qiang Wang, Hong Zhang, Juan Huang, Nan Xia, Tong Li, Qiang Xia
Xanthan gum is a natural polysaccharide produced by fermentation with Xanthamonas campestris. It consists of a primary chain of β-D-(1,4)-glucose backbone, which has a branching trisaccharide side chain composed of β-D-(1,2)-mannose, attached to β-D-(1,4)-glucuronic acid, which terminates in a final β-d-mannose. The secondary structure of xanthan gum has been shown to consist of a fivefold helical structure (Song et al., 2006; Pongjanyakul and Puttipipatkhachorn, 2007). This polysaccharide is generally recognised as a safe (GRAS) compound and widely used as a stabiliser, a viscous agent and a structure provider in food, cosmetics and pharmaceuticals areas (Arimura et al., 2011). Moreover, it has been proved that xanthan gum could form hydrogels when aqueous solutions are annealed at a high temperature for a period of time and subsequently cooled (annealing and subsequent cooling induced gelation) (Fujiwara et al., 2000), and xanthan solutions often exhibit better gelation characteristics and higher viscosities than other gums at the same low concentration (Mittal and Barbut, 1994). Therefore, xanthan gum is selected to establish a network structure which is responsible for retention of SDEDDS dispersion.
Enhancement of levodopa stability when complexed with β-cyclodextrin in transdermal patches
Published in Pharmaceutical Development and Technology, 2018
Rana Obaidat, Nizar Al-Shar'i, Bassam Tashtoush, Tamara Athamneh
The selection of a polymeric material in designing a transdermal drug-delivery system (TDDS) is critical to achieve an optimal effect6,11,13–15. Carbopols are biodegradable, mucoadhesive and environmentally responsive polymers and are considered as “smart gels”16,17. Due to their stability under variable temperatures (e.g. sterilization), carbopols can be used as a vehicle for pharmaceutical bioadhesive preparations (transdermal and buccal)17. Xanthan gum is a high molecular weight polysaccharide gum with a hydrophilic polymer4,18. Xanthan is gaining more attention not only because of its biocompatibility and inertness but also because it retards drug release and provides time-independent release kinetics18.
Formulation and evaluation of carrot seed oil-based cosmetic emulsions
Published in Journal of Cosmetic and Laser Therapy, 2019
Shalini Singh, Alka Lohani, Arun Kumar Mishra, Anurag Verma
Xanthan gum was used as an emulsion stabilizer. It is nontoxic and nonirritating. Xanthan gum is soluble in cold and hot water and shows a high degree of viscosity even in low concentrations. The high viscosity of xanthan gum at low shear rates effectively stabilizes creams and lotions, which are primarily oil-in-water emulsions. Xanthan gum keeps emulsions stable over a broad temperature and pH range. It also assures lotion flowability even upon aging. Furthermore, xanthan gum stabilizes the oil phase of creams and lotions and delivers the active ingredients to the skin in a uniform manner. With its high viscosity at rest, xanthan gum effectively suspends insoluble ingredients in cosmetics. It can be used in combination with other thickeners and stabilizers to improve the texture, flow behavior, stability, and appearance. Xanthan gum produces a large increase in the viscosity of a liquid with the addition of a very small amount of gum. Generally, 1%w/v, but as little as 0.1w/v%, can be used in many applications. Xanthan gum solutions are pseudoplastic, i.e., they show shear thinning flow behavior. This pseudoplasticity imparts a smooth texture to the final product and provides a pleasant application.
Related Knowledge Centers
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- Xanthomonas Campestris